After en bloc resection of the heart and lungs, all cardiac structures were examined macroscopically, including the right atrium, tricuspid valve, right ventricle, and pulmonic valve, as well as the main pulmonary artery, right and left pulmonary artery for rupture, perforation, dissection, or hemorrhage. Lung specimens were examined macroscopically for hemorrhage, edema, or atelectasis. After partial fixation in 4% formaldehyde solution, lung specimens were cut transversely into 1-cm sections and evaluated macroscopically for perforation and dissection of treated and untreated pulmonary artery segments. After partial fixation in 4% formaldehyde solution, lung specimens were cut transversally into 1-cm sections and evaluated macroscopically for perforation and dissection of treated and untreated pulmonary artery segments. After complete fixation, representative samples (8-10 per lung) were paraffin-embedded, cut into 3 micrometer sections, and stained with hematoxylin-eosin and van Gieson combined with Weigert's method for elastic fiber staining (Weigert-van Gieson) for histological evaluation of the vessel wall integrity. The microscopic endpoints included perforation, dissection, or hemorrhage of treated vascular segments.